Turbine engine comprising a steam system

Abstract

A turbine engine for an aircraft includes a turbocharged engine, a fan having a fan shaft coupled to the turbocharged engine, and a steam system. A steam system is fluidly coupled to the core air flow path at a plurality of steam injection locations to selectively inject steam into the core air flow path at each of the plurality of steam injection locations using a steam flow control valve. The plurality of steam injection locations includes (i) an upstream steam injection location positioned to inject steam into the core air flow path at or upstream of a main combustion region of the combustor; and (ii) a downstream steam injection location positioned to inject steam into the core air flow path downstream of the main combustion zone.

Description

Technical Field

[0001] The present disclosure generally relates to a turbine engine including a steam system. Background Art

[0002] Turbine engines used in aircraft typically include a fan and a core section arranged in fluid communication with each other. A combustor is arranged in the core section to generate combustion gases for driving a turbine in the core section of the turbine engine. Brief Description of the Drawings

[0003] The features and advantages of the present disclosure will be apparent from the following description of various exemplary embodiments shown in the drawings, wherein like reference numerals generally represent the same, functionally similar, and / or structurally similar elements.

[0004] Figure 1 is a schematic cross-sectional view of a turbine engine including a steam system taken along the longitudinal centerline axis of the turbine engine according to the present disclosure.

[0005] Figure 2 is according to the present disclosure Figure 1 of a turbine engine and a steam system.

[0006] Figure 3A is Figure 1 a detailed view of a portion of the turbine engine shown in Figure 1 showing detail 3A in Figure 3A shows a steam injection system according to a preferred embodiment.

[0007] Figure 3B is a detailed view of a portion of a turbine engine according to another preferred embodiment, showing a steam injection system.

[0008] Figure 4 is a detailed view of a portion of a turbine engine according to another preferred embodiment, showing a steam injection system.

[0009] Figure 5 is a detailed view of a portion of a turbine engine according to another preferred embodiment, showing a steam injection system.

[0010] Figure 6 is a detailed view of a portion of a turbine engine according to another preferred embodiment, showing a steam injection system.

[0011] Figure 7 is a detailed view of a portion of a turbine engine according to another preferred embodiment, showing a steam injection system. Detailed Description

[0012] The features, advantages, and embodiments of the present disclosure are set forth or are apparent from the following detailed description, the drawings, and the claims. Additionally, the following detailed description is exemplary and is intended to provide further explanation without limiting the scope of the claimed present disclosure.

[0013] Various embodiments are discussed in detail below. Although specific embodiments are discussed, this is for illustrative purposes only. Those skilled in the relevant art will recognize that other components and configurations may be used without departing from the spirit and scope of the present disclosure.

[0014] As used herein, the terms "first," "second," etc. may be used interchangeably to distinguish one component from another and are not intended to denote the position or importance of the individual components.

[0015] The terms "front" and "rear" refer to relative positions within a gas turbine engine or vehicle and refer to the normal operating attitude of the gas turbine engine or vehicle. For example, for a gas turbine engine, front refers to a position closer to the engine inlet, and rear refers to a position closer to the engine nozzle or exhaust outlet.

[0016] The terms "upstream" and "downstream" refer to the relative direction with respect to the fluid flow in a fluid path. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction towards which the fluid flows.

[0017] The terms "coupled," "fixed," "attached," "connected," etc. refer to direct coupling, fixing, attaching, or connecting, as well as indirect coupling, fixing, attaching, or connecting through one or more intermediate components or features, unless otherwise specified herein.

[0018] As used herein, the terms "axial" and "axially" refer to a direction and orientation that extends substantially parallel to the centerline of a turbine engine. Additionally, the terms "radial" and "radially" refer to a direction and orientation that extends substantially perpendicular to the centerline of a turbine engine. Further, as used herein, the terms "circumferential" and "circumferentially" refer to a direction and orientation that extends in an arcuate manner around the centerline of a turbine engine.

[0019] When discussed in the context of the radial direction, "inner" and "outer" refer to positions relative to the longitudinal centerline of a component.

[0020] As used herein, the "bypass ratio" of a turbine engine is the ratio of the bypass air that bypasses the turbine engine to the core air that enters the core of the turbocharged engine of the turbine engine.

[0021] As used herein, the "compression ratio" of a compressor is the ratio of the compressor outlet pressure at the outlet of the compressor to the compressor inlet pressure at the inlet of the compressor. The compressor outlet pressure and the compressor inlet pressure are measured as static air pressures perpendicular to the direction of the core air flow through the compressor.

[0022] As used herein, the "pressure expansion ratio" of a turbine is the ratio of the pressure at the inlet of the turbine to the pressure at the outlet of the turbine.

[0023] The singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.

[0024] Herein, as well as throughout the specification and claims, range limitations are combined and interchanged. Such ranges are identified and include all subranges subsumed therein unless the context or language indicates otherwise. For example, all ranges disclosed herein include the endpoints, and the endpoints can be combined independently of each other.

[0025] As described above, the burner is disposed in the core section of the turbine engine to generate combustion gases for driving the turbine in the core section. Not all of the energy and heat generated by the burner are used to drive the turbine in the turbine section. Instead, some of the waste heat is discharged through the injection exhaust nozzle section in a conventional turbine engine. The turbine engine discussed herein includes a steam system for recovering some of the energy from the waste heat by generating steam and driving a steam turbine. After flowing through the steam turbine, the steam can be injected into the core air flow path, and more specifically, into the burner. To achieve a greater benefit of the increased mass flow within the core air flow, the steam is preferably injected into the core air in a range of 20% to 50% of the mass flow through the core air flow path. While it is beneficial for some of the steam to flow through the main combustion zone of the burner, the steam at these mass flows (or water-air ratios) can cause flame stability problems and flame dynamics problems during the fuel combustion process, especially for highly reactive fuels such as diatomic hydrogen. Instead, as discussed herein, the steam can be injected into the core air flow path at multiple locations, with a portion of the steam flowing through the main combustion zone. In this way, the water-air ratio of the main air flowing through the main combustion zone can be maintained at a sufficiently low level to achieve good flame performance.

[0026] Now referring to the drawings, Figure 1 is a schematic cross-sectional view of a turbine engine 10 including a steam system 100 taken along the longitudinal centerline axis 12 (provided for reference) of the turbine engine 10 according to an embodiment of the present disclosure. As Figure 1As shown, the turbomachine 10 has an axial direction A (extending parallel to the longitudinal centerline axis 12) and a radial direction R orthogonal to the axial direction A. Generally, the turbomachine 10 includes a fan section 14 and a turbocharged engine 16 disposed downstream of the fan section 14.

[0027] The turbocharged engine 16 includes, in series flow relationship, a compressor section 21, a combustion section 26, and a turbine section 27. The turbocharged engine 16 is substantially enclosed within a casing 18, which is substantially tubular and defines a core inlet 20, as Figure 1 shown, the core inlet 20 may be annular. As Figure 1 schematically shown in, the compressor section 21 includes a booster or low-pressure compressor (LPC) 22, downstream of which is immediately followed by a high-pressure compressor (HPC) 24. The combustion section 26 is downstream of the compressor section 21. The turbine section 27 is downstream of the combustion section 26 and includes a high-pressure turbine (HPT) 28, downstream of which is immediately followed by a low-pressure turbine (LPT) 30. The turbocharged engine 16 further includes an exhaust nozzle section 32, a high-pressure (HP) shaft 34 or spool, and a low-pressure (LP) shaft 36 located downstream of the turbine section 27. The compressor section 21, the burner 26, the turbine section 27, and one or more core exhaust nozzles 32 together define a core air flow path 33. The HP shaft 34 drivingly connects the HPT 28 to the HPC 24. The HPT 28 and the HPC 24 rotate synchronously via the HP shaft 34. The LP shaft 36 drivingly connects the LPT 30 to the LPC 22. The LPT 30 and the LPC 22 rotate synchronously via the LP shaft 36.

[0028] For Figure 1 the embodiment shown in, the fan section 14 includes a fan 38 (e.g., a variable pitch fan) having a plurality of fan blades 40, which are coupled to a disk 42 in a spaced-apart manner. As Figure 1 shown, the fan blades 40 extend generally radially outward from the disk 42 in the radial direction R. In the case of a variable pitch fan, by means of the fan blades 40 being operatively coupled to an actuator 44, the plurality of fan blades 40 are rotatable relative to the disk 42 about a pitch axis P, and the actuator 44 is configured to collectively change the pitch of the fan blades 40 in unison. The fan blades 40, the disk 42, and the actuator 44 together rotate about the longitudinal centerline axis 12 via a fan shaft 45, and the fan shaft 45 is powered by the LP shaft 36 via a power gearbox (also referred to as a gearbox assembly 46). Thus, the fan 38 is drivingly coupled to and powered by the turbocharged engine 16, and the turbomachine 10 is an indirectly driven engine. The gearbox assembly 46 is in Figure 1is schematically shown. The gearbox assembly 46 can be a reduction gearbox assembly that includes a plurality of gears for adjusting the rotational speed of the fan shaft 45 as power is transmitted from the LP shaft 36 to the fan shaft 45, thereby adjusting the rotational speed of the fan 38 relative to the LP shaft 36.

[0029] Still referring to Figure 1 the exemplary embodiment of, the disc 42 is covered by a rotatable fan hub 48 that has an aerodynamic profile to facilitate air flow through the plurality of fan blades 40. Additionally, the fan section 14 includes an annular fan casing or nacelle 50 that circumferentially surrounds at least a portion of the fan 38 and / or the turbomachine 16. The nacelle 50 is supported relative to the turbomachine 16 by a plurality of circumferentially spaced outlet guide vanes 52. Further, a downstream section 54 of the nacelle 50 extends over an outer portion of the turbomachine 16 and, together with the outer casing 18, defines a bypass air flow passage 56 therebetween. One or more core exhaust nozzles 32 may extend through the nacelle 50 and be formed therein. In this embodiment, the one or more core exhaust nozzles 32 include one or more discrete nozzles that are circumferentially spaced about the nacelle 50. Other arrangements of the one or more core exhaust nozzles 32 may also be employed, such as, for example, including a single core exhaust nozzle that is annular or partially annular about the nacelle 50.

[0030] During operation of the turbine engine 10, a volume of air 58 enters the turbine engine 10 through the nacelle 50 and / or the inlet 60 of the fan section 14. As the volume of air 58 passes through the fan blades 40, a first portion of the air (also referred to as bypass air 62) is directed or guided into the bypass air flow passage 56, while a second portion of the air (also referred to as core air 64) is directed or guided through the core inlet 20 into an upstream section of the core air flow path 33. The ratio between the bypass air 62 and the core air 64 is referred to as the bypass ratio. In some embodiments, the bypass ratio is greater than 18:1, achieved by the steam system 100, which will be described in further detail below. The LPC 22 then increases the pressure of the core air 64, producing compressed air 65. The compressed air 65 is directed through the HPC 24 and further compressed before being directed into the combustor 26, where the compressed air 65 is mixed with fuel 67 and ignited to produce combustion gases 66 (combustion products). Each of the LPC 22 and the HPC 24 may use one or more stages, where each subsequent stage further compresses the compressed air 65. The compression ratio of the HPC 24 is greater than 20:1, preferably in the range of 20:1 to 40:1. The compression ratio is the ratio of the pressure of the last stage of the HPC 24 to the pressure of the first stage of the HPC 24. The steam system 100 can achieve a compression ratio greater than 20:1, as described in further detail below.

[0031] The combustion gas 66 is directed into the HPT 28 and expands through the HPT 28, where a portion of the thermal energy and / or kinetic energy from the combustion gas 66 is extracted via one or more stages of the HPT stator vanes 68 and the HPT rotor blades 70 coupled to the HP shaft 34. This causes the HP shaft 34 to rotate, thereby supporting the operation of the HPC 24 (self-sustaining cycle). In this way, the combustion gas 66 does work on the HPT 28. Then, the combustion gas 66 is directed into the LPT 30 and expands through the LPT 30. Here, a second portion of the thermal energy and / or kinetic energy is extracted from the combustion gas 66 via one or more stages of the LPT stator vanes 72 and the LPT rotor blades 74 coupled to the LP shaft 36. This causes the LP shaft 36 to rotate, thereby supporting the operation of the LPC 22 (self-sustaining cycle) and the rotation of the fan 38 via the gearbox assembly 46. In this way, the combustion gas 66 does work on the LP turbine 30. Each of the HPT 28 and the LPT 30 can utilize one or more stages. The compression ratio of the HPC 24 is in the range of 20:1 to 40:1, which results in a pressure expansion ratio of the HPT 28 in the range of 1.5:1 to 4:1, and a pressure expansion ratio of the LPT 30 in the range of 4.5:1 to 28:1.

[0032] After the combustion gas 66 is directed through the steam system 100 (discussed below), it is subsequently directed through one or more core exhaust nozzles 32 of the turbofan engine 16 to provide propulsion thrust. While the core air 64 flows through the core air flow path 33, the bypass air 62 is directed through the bypass air flow channel 56 before being discharged from the fan bypass nozzle 76 of the turbofan engine 10, also providing propulsion thrust. The HPT 28, the LPT 30, and one or more core exhaust nozzles 32 at least partially define a hot gas path 78 for directing the combustion gas 66 through the turbofan engine 16.

[0033] As described above, the compressed air 65 (core air 64) is mixed with the fuel 67 in the combustor 26 to form a fuel and air mixture, which is burned to produce the combustion gas 66 (combustion products). The fuel 67 can include any type of fuel for a turbofan engine, such as, for example, sustainable aviation fuel (SAF), including biofuels, Jet A, or other hydrocarbon fuels. The fuel 67 can also be a hydrogen-based fuel (H2), and although the hydrogen-based fuel can include a mixture with hydrocarbon fuels, the fuel 67 used herein is preferably unmixed and is referred to herein as hydrogen fuel. In some embodiments, the hydrogen fuel can include substantially pure hydrogen molecules (i.e., diatomic hydrogen). The fuel 67 can also be a cryogenic fuel. For example, when using hydrogen fuel, the hydrogen fuel can be stored in a liquid phase at a low temperature.

[0034] The turbine engine 10 includes a fuel system 80 for supplying fuel 67 to a combustor 26. The fuel system 80 includes a fuel tank 82 for storing the fuel 67 therein and a fuel delivery assembly 84. The fuel tank 82 may be located on an aircraft (not shown) to which the turbine engine 10 is attached. Although Figure 1 a single fuel tank 82 is shown, the fuel system 80 may include any number of fuel tanks 82 as needed. The fuel delivery assembly 84 delivers the fuel 67 from the fuel tank 82 to the combustor 26. The fuel delivery assembly 84 includes one or more pipelines, conduits, pipes, tubes, etc., configured to deliver the fuel 67 from the fuel tank 82 to the combustor 26. The fuel delivery assembly 84 also includes a pump 86 to direct the flow of fuel 67 through the fuel delivery assembly 84 to the combustor 26. Thus, the pump 86 pumps the fuel 67 from the fuel tank 82 through the fuel delivery assembly 84 and into the combustor 26. The fuel system 80, and more specifically, the fuel tank 82 and the fuel delivery assembly 84, either jointly or individually, may be a fuel source for the combustor 26.

[0035] In some embodiments, for example, when the fuel 67 is hydrogen fuel, the fuel system 80 includes one or more vaporizers 88 (shown in dashed lines) and a metering valve 90 (shown in dashed lines) that are in fluid communication with the fuel delivery assembly 84. In this example, the hydrogen fuel is stored as liquid hydrogen fuel in the fuel tank 82. The one or more vaporizers 88 heat the liquid hydrogen fuel flowing through the fuel delivery assembly 84. The one or more vaporizers 88 are positioned in the flow path of the fuel 67 between the fuel tank 82 and the combustor 26 and downstream of the pump 86. The one or more vaporizers 88 are in thermal communication with at least one heat source, such as, for example, waste heat from the turbine engine 10 and / or from one or more systems of the aircraft (not shown). The one or more vaporizers 88 heat the liquid hydrogen fuel, and the liquid hydrogen fuel is converted into gaseous hydrogen fuel within the one or more vaporizers 88. The fuel delivery assembly 84 directs the gaseous hydrogen fuel into the combustor 26.

[0036] The metering valve 90 is positioned downstream of the one or more vaporizers 88 and the pump 86. The metering valve 90 receives hydrogen fuel that is in a substantially fully gaseous phase or in a substantially fully supercritical phase. The metering valve 90 supplies a fuel flow to the combustor 26 in a desired manner. More specifically, the metering valve 90 supplies a desired volume of hydrogen fuel to a fuel manifold, for example, at a desired flow rate, the fuel manifold including one or more fuel injectors that inject the hydrogen fuel into the combustor 26. The fuel system 80 may include any components for supplying the fuel 67 from the fuel tank 82 to the combustor 26 as needed.

[0037] The turbine engine 10 includes a steam system 100 that is in fluid communication with one or more core exhaust nozzles 32 and fan bypass nozzles 76. As combustion gases 66 flow through the steam system 100, the steam system 100 extracts steam from the combustion gases 66, as described in further detail below.

[0038] Figure 1 The turbine engine 10 shown in is only an example. In other exemplary embodiments, the turbine engine 10 may have any other suitable configuration. For example, in other exemplary embodiments, the fan 38 may be configured in any other suitable manner (e.g., as a fixed pitch fan), and further may be supported using any other suitable fan frame configuration. Additionally, in other exemplary embodiments, any other suitable number or configuration of compressors, turbines, shafts, or combinations thereof may be provided. In other exemplary embodiments, aspects of the present disclosure may be incorporated into any other suitable turbine engine, such as, for example, a turbofan engine, a propfan engine, and / or a turboprop engine.

[0039] Figure 2 is in accordance with the present disclosure Figure 1 of the turbine engine 10 and the steam system 100. For clarity, the turbine engine 10 is schematically shown in, and Figure 2 some components are not shown in. The steam system 100 includes a boiler 102, a condenser 104, a water separator 106, a water pump 108, and a steam turbine 110. Figure 2

[0040] The boiler 102 is a heat exchanger that vaporizes liquid water from a water source to produce steam or water vapor, as described in further detail below. Thus, the boiler 102 is a steam source. Specifically, the boiler 102 is an exhaust gas - water heat exchanger. The boiler 102 is in fluid communication with the hot gas path 78 ( Figure 1 ) and is positioned downstream of the LPT 30. The boiler 102 is also in fluid communication with the water pump 108, as described in further detail below. The boiler 102 may include any type of boiler or heat exchanger for extracting heat from the combustion gases 66 and vaporizing the liquid water into steam or water vapor as the liquid water and the combustion gases 66 flow through the boiler 102.

[0041] The condenser 104 is a heat exchanger that further cools the combustion gases 66 as the combustion gases 66 flow through the condenser 104, as described in further detail below. Specifically, the condenser 104 is an air - exhaust gas heat exchanger. The condenser 104 is in fluid communication with the boiler 102 and is positioned within the bypass air flow path 56. The condenser 104 may include any type of condenser for condensing water (e.g., in liquid form) from the exhaust (e.g., the combustion gases 66).​

[0042] The water separator 106 is in fluid communication with the condenser 104 and is configured to receive the cooled exhaust gas (combustion gas 66) entrained with condensed water therein. The water separator 106 is also in fluid communication with one or more core exhaust nozzles 32 and with the water pump 108. The water separator 106 includes any type of water separator configured to separate water from the exhaust gas. For example, the water separator 106 can include a cyclone separator that uses vortex separation to separate water from air. In such an embodiment, the water separator 106 generates a swirling flow within the water separator 106 to separate water from the cooled exhaust gas. In Figure 2 the figure, the water separator 106 is schematically shown in the nacelle 50, but the water separator 106 can be located at other locations within the turbine engine 10, such as, for example, radially inside the nacelle 50, closer to the turbocharger 16. The water separator 106 can be driven to rotate by one of the engine shafts, such as the HP shaft 34 or the LP shaft 36. As described above, the boiler 102 receives liquid water from a water source to generate steam or water vapor. In Figure 2 the illustrated embodiment, the condenser 104 and the water separator 106 are, individually or jointly, a water source for the boiler 102.

[0043] The water pump 108 is in fluid communication with the water separator 106 and with the boiler 102. The water pump 108 is in fluid communication with the condenser 104 via the water separator 106. The water pump 108 can be any suitable pump, such as a centrifugal pump or a positive displacement pump. The water pump 108 directs the separated liquid water 124 through the boiler 102, where the water 124 is converted back to steam. This steam is sent through the steam turbine 110 and then injected into the core air flow path 33, such as into the burner 26.

[0044] Figure 2 The steam system 100 shown in the figure includes a water tank 112 fluidly connected to the water separator 106 for collecting the water 124 condensed by the condenser 104 and separated by the water separator 106. The water tank 112 can be positioned between the water separator 106 and the water pump 108. The water pump 108 can draw water 124 from the water tank 112 and direct the water 124 into the boiler 102 at a desired flow rate. However, in some embodiments, the water tank 112 can be omitted from the steam system 100.

[0045] In operation, combustion gas 66 (also referred to as exhaust gas) flows from the LPT 30 into the boiler 102. The combustion gas 66 transfers heat to the water 124 (e.g., in liquid form) within the boiler 102, as further detailed below. Then, the combustion gas 66 flows into the condenser 104. The condenser 104 condenses the water 124 (e.g., in liquid form) from the combustion gas 66. The bypass air 62 flows through the bypass air flow passage 56 and flows over or through the condenser 104, extracting heat from the combustion gas 66, cooling the combustion gas 66 and condensing the water 124 from the combustion gas 66 to produce an exhaust-water mixture 120. Then, as detailed above, the bypass air 62 is discharged from the turbine engine 10 through the fan bypass nozzle 76 to produce thrust. Thus, the condenser 104 can be positioned within the bypass air flow passage 56.

[0046] The exhaust-water mixture 120 flows into the water separator 106. The water separator 106 separates the water 124 of the exhaust-water mixture 120 from the exhaust gas to produce a separate exhaust gas 122 and water 124. As detailed above, the exhaust gas 122 is discharged from the turbine engine 10 through one or more core exhaust nozzles 32 to produce thrust. The boiler 102, the condenser 104, and the water separator 106 thus also define a part of the hot gas path 78 (see Figure 1 ) for directing the combustion gas 66, the exhaust-water mixture 120, and the exhaust gas 122 through the steam system 100 of the turbine engine 10.

[0047] The water pump 108 pumps the water 124 (e.g., in liquid form) through one or more water pipelines (as indicated by the arrow of the water 124 in Figure 2 ), and the water 124 flows through the boiler 102. As the water 124 flows through the boiler 102, the combustion gas 66 flowing through the boiler 102 transfers heat to the water 124 to vaporize the water 124 and produce steam 126 (e.g., vapor). The steam turbine 110 includes one or more stages of steam turbine blades (not shown) and steam turbine stators (not shown). The steam 126 flows from the boiler 102 into the steam turbine 110 through one or more steam pipelines (as indicated by the arrow of the steam 126 in Figure 2 ), causing the steam turbine blades of the steam turbine 110 to rotate, thereby generating additional work in an output shaft (e.g., one of the engine shafts) connected to the turbine blades of the steam turbine 110.

[0048] As described above, the turbocharged engine 16 includes a shaft, also referred to as the engine shaft, which couples various rotating components of the turbocharged engine 16 and other thrust generating components such as the fan 38. In Figure 1In the turbocharged engine 16 shown, these engine shafts include the HP shaft 34 and the LP shaft 36. The steam turbine 110 is coupled to one of the engine shafts of the turbocharged engine 16, such as the HP shaft 34 or the LP shaft 36. In the illustrated embodiment, the steam turbine 110 is coupled to the LP shaft 36. When steam 126 flows through the steam turbine 110 from the boiler 102, the steam turbine 110 converts the kinetic energy of the gas into mechanical work in the LP shaft 36. The low-temperature steam (as steam 128) leaving the steam turbine 110 is then injected into the core air flow path 33, such as into the burner 26, upstream of the burner 26, or downstream of the burner 26. The steam 128 flows from the steam turbine 110 through one or more steam lines to the core air flow path 33. The steam 128 injected into the core air flow path 33 adds mass flow to the core air 64, such that less core air 64 is required to produce the same amount of work through the turbine section 27. Thus, the steam system 100 extracts additional work from the heat in the exhaust gas, which would otherwise be wasted. The steam 128 injected into the core air flow path 33 is in the range of 20% to 50% of the mass flow through the core air flow path 33.

[0049] The pressure expansion ratio of the steam turbine 110 can be in the range of 2:1 to 6:1. The pressure expansion ratio is the ratio of the pressure at the inlet of the steam turbine 110 to the pressure at the outlet of the steam turbine 110. When the steam system 100 recovers approximately 70% of the water 124 and converts the water 124 into steam 126, the steam turbine 110 can contribute approximately 25% of the power to the LP shaft 36 (or the HP shaft 34). The pressure expansion ratio of the steam turbine 110 is in the range of 2:1 to 6:1, the pressure expansion ratio of the LPT 30 is in the range of 4.5:1 to 28:1, and the steam 128 contributes 20% to 50% of the mass flow through the core air flow path 33. The steam turbine 110 expands the steam 126, thereby reducing the energy of the steam 128 leaving the steam turbine 110 and reducing the temperature of the steam 128 to approximately the temperature of the compressed air 65 discharged from the HPC 24 (see Figure 1 ). Such a configuration enables the steam 128 to reduce hot spots generated by fuel combustion in the burner 26 (e.g., especially when the fuel is supercritical hydrogen or gaseous hydrogen).

[0050] The steam 128 injected into the core air flow path 33 also enables the HPT 28 to achieve a greater energy output with fewer stages of the HPT 28 compared to an HPT without the benefits of the present disclosure. For example, the additional mass flow of the steam 128 from the steam passing through the turbine section 27 contributes to generating a greater energy output. Thus, due to the higher mass flow leaving the combustor 26 (generated by steam injection), the HPT 28 can have only one of the greater number of stages (e.g., 10, 11, or 12 stages of the HPC 24) that can continuously drive the HPC 24. The steam 128 injected into the core air flow path 33 enables the HPT 28 to have only one of the multiple stages that drive the HPC 24 without reducing the amount of work generated by the HPT 28 (compared to an HPT without the benefits of the present disclosure), while also reducing the weight of the HPT 28 and increasing the efficiency of the HPT 28 (compared to an HPT without the benefits of the present disclosure).

[0051] Since the steam 126 adds mass flow, less core air 64 is required (see Figure 1 ), and the compression ratio of the HPC 24 can be increased compared to an HPC without the benefits of the present disclosure. Thus, the compression ratio of the HPC 24 is greater than 20:1. In some embodiments, the compression ratio of the HPC 24 is in the range of 20:1 to 40:1. Therefore, the compression ratio of the HPC 24 is increased, thereby improving the thermal efficiency of the turbine engine 10 compared to an HPC and a turbine engine without the benefits of the present disclosure. Additionally, due to the added mass flow in the turbocharged engine 16 provided by the injection of the steam 126, 128 into the turbocharged engine 16, the HPC 24 can have a reduced throat area. Thus, the HPC 24 has a reduced size (e.g., outer diameter) and reduced weight compared to a turbine engine without the benefits of the present disclosure.

[0052] In some embodiments, the HPC stator vanes of at least two stages of the HPC 24 are variable stator vanes that are controlled to pitch about a pitch axis to change the pitch of the HPC stator vanes. In some embodiments, the HPC 24 includes one or more compressor bleed valves that are controlled to open to bleed off a portion of the compressed air 65 from the HPC 24 (see Figure 1 ). The one or more compressor bleed valves are preferably positioned between the fourth stage of the HPC 24 and the last stage of the HPC 24. The HPC stator vanes are variable stator vanes, and the one or more compressor bleed valves contribute to balancing the air flow (e.g., compressed air 65) through all stages of the HPC 24. This balance, in combination with the steam 128 injected into the core air flow path 33, enables the number of stages of the HPC 24 to include ten to twelve stages such that the compression ratio is greater than 20:1 and preferably in the range of 20:1 to 40:1.

[0053] The additional work extracted from the steam system 100 and the steam 128 injected into the core air flow path 33 enable the turbocharged engine 16 ( Figure 1 ) to be reduced in size, thereby increasing the bypass ratio of the turbo engine 10 compared to a turbo engine without the benefits of the present disclosure. Thus, the bypass ratio of the turbo engine 10 is greater than 18:1, preferably in the range of 18:1 to 100:1, more preferably in the range of 25:1 to 85:1, and most preferably in the range of 28:1 to 70:1. Thus, the steam system 100 can achieve an increased bypass ratio, where the turbo engine 10 can move a greater amount of air through the bypass, thereby reducing the pressure ratio of the fan 38 and increasing the efficiency of the turbo engine 10 compared to a turbo engine without the benefits of the present disclosure.

[0054] Figure 3A is a detailed view of a portion of the turbocharged engine 16, showing Figure 1 detail 3A in Figure 3A shows a burner 26, a portion of the HPC 24, a portion of the HPT 28, and a portion of the LPT 30. Figure 3A Also shown is a first steam injection system 200 according to a preferred embodiment. The burner 26 is an annular burner (i.e., annular about the longitudinal centerline axis 12), which includes a combustion chamber 130 defined between an inner liner 132 and an outer liner 134. Each of the inner liner 132 and the outer liner 134 is annular about the longitudinal centerline axis 12 of the turbo engine 10 ( Figure 1 ) and thus can extend circumferentially about the turbo engine 10. The burner 26 also includes a burner housing 136, which is also annular about the longitudinal centerline axis 12 of the turbo engine 10. The burner housing 136 extends circumferentially around the inner liner 132 and the outer liner 134, and the inner liner 132 and the outer liner 134 are located radially inside the burner housing 136. The burner 26 also includes a dome 138 mounted to the front end of each of the inner liner 132 and the outer liner 134. The dome 138 defines the upstream (or front end) of the combustion chamber 130.

[0055] A plurality of mixer assemblies 140 ( Figure 3A only one is shown in Figure 1 ) are spaced apart around the dome 138. The plurality of mixer assemblies 140 are circumferentially spaced apart about the longitudinal centerline axis 12 of the turbo engine 10 ( Figure 1)A fuel nozzle 142 that receives fuel 67. The fuel 67 is injected into the combustion chamber 130 through one or more orifices formed in the mixer assembly 140. The mixer assembly 140 can be any suitable mixer assembly, including a rich-burning mixer assembly or a lean-burning mixer assembly, such as a twin-annular pre-mixing swirler (TAPS).

[0056] As described above, the compressor section 21 including the HPC 24 pressurizes the air, and the burner 26 receives an annular flow of the pressurized air from the discharge outlet of the HPC 24 (compressor discharge outlet 144). This air can be referred to as compressor discharge pressure air 150. The compressor discharge outlet 144 can be positioned to discharge the compressor discharge pressure air 150 into the mixing chamber 146, and then a portion of the compressor discharge pressure air 150 flows as primary air 152 into the mixer assembly 140. The mixer assembly 140 can include a plurality of swirler vanes that are part of a swirler and are configured to form a swirl and generate turbulence in the primary air 152 flowing through the mixer assembly 140. The fuel nozzle 142 injects the fuel 67 into the turbulent air flow of the primary air 152, and the turbulence promotes rapid mixing of the fuel 67 with the primary air 152, producing a fuel-air mixture.

[0057] The fuel-air mixture is provided from the mixer assembly 140 to the combustion chamber 130 for combustion. Ignition of the fuel-air mixture is accomplished by the igniter 148, and the resulting combustion gases 66 flow in the axial direction A of the turbine engine 10 toward and into the annular turbine nozzle of the HPT 28. Most of the fuel 67 injected by the fuel nozzle 142 burns in the primary combustion zone 135 in the region of the combustion chamber 130 immediately downstream of the mixer assembly 140. The turbine nozzle is defined by an annular flow passage that includes a plurality of radially extending, circumferentially spaced HPT stator vanes 68 that turn the gases so that they flow at an angle and impinge on a plurality of HPT rotor blades 70 of the turbine rotor of the HPT 28. The HPT rotor blades 70 are circumferentially spaced, and the HPT stator vanes 68 are upstream of the HPT rotor blades 70. The rotor can be, for example, a disk or a blisk that is drivingly connected to the HP shaft 34. As discussed above, the steam system 100 is capable of using a single-stage HPT 28, and Figure 3A only one stage is depicted in, but other HPTs can also be used, including HPTs having two or more stages.

[0058] Another portion of the compressor discharge pressure air 150 is dilution air 154 (also referred to as secondary air). The dilution air 154 flows around the outer sides of the inner liner 132 and the outer liner 134 and is introduced into the combustion chamber 130 through one or more dilution holes 156 formed in the inner liner 132 and the outer liner 134 at a location downstream of the mixer assembly 140. The dilution air 154 helps to extinguish the combustion gases from the primary combustion zone 135 before being introduced into the turbine section 27. The dilution air 154 bypasses the primary combustion zone 135 and is introduced into the combustion chamber 130 downstream of the primary combustion zone 135.

[0059] A third portion of the compressor discharge pressure air 150 can be directed as HPT cooling air 158 into the HPT 28. The HPT cooling air 158 can be drawn from the dilution air 154 and directed into the HPT rotor blades 70 and, more specifically, cools the HPT rotor blades 70 through cooling channels formed within the HPT rotor blades 70.

[0060] The steam system 100( Figure 2 ) is fluidly coupled to the core air flow path 33 via a steam delivery assembly 212. The steam delivery assembly 212 includes one or more pipelines, conduits, pipes, tubes, etc., configured to deliver steam 128 from a steam source (such as a boiler 102) to the core air flow path 33. The steam delivery assembly 212 is fluidly connected to the core air flow path 33 at a plurality of steam injection locations 220 to selectively inject steam 128 into the core air flow path 33 at each of the plurality of steam injection locations 220.

[0061] One of the plurality of steam injection locations 220 is a primary steam injection location 222, which is positioned to inject at least a portion of the steam 128 into the primary air 152. The steam 128 can be injected into the primary air 152 at a certain steam flow rate to achieve a desired water-air ratio (WAR) in the primary air 152. More specifically, as Figure 3A shown, the primary steam injection location 222 is positioned to inject the primary steam 232 into the mixing chamber 146 to mix with the primary air 152 before the primary steam 232 flows through the mixer assembly 140 and upstream of the primary combustion zone 135. As will be further discussed below, the primary steam 232 is a portion of the steam 128 that is injected into the core air flow path 33. The primary steam injection location 222 may also be referred to herein as the upstream steam injection location. As will be further discussed below, by injecting the steam 128 into the mixing chamber 146, the steam 128 can also be mixed with the dilution air 154 and the HPT cooling air 158.

[0062] Steam 128 can be injected into the core air flow path 33 in a range of 5% to 50% of the mass flow through the core air flow path 33 (i.e., 5% to 50% WAR), and this parameter is referred to herein as the total WAR. To achieve the benefits of waste heat recovery discussed herein, this amount of steam 128 (water vapor) is beneficial when flowing through the turbine section 27 and more specifically through the HPT 28 and the LPT 30. Additionally, the desired total WAR can vary throughout the flight of the aircraft depending on the operating conditions. For example, a total WAR of approximately 25% may be required under cruise conditions or high altitude conditions, but a higher total WAR, such as approximately 40%, may be required during high power operations (such as takeoff and climb). Under cruise conditions, the total WAR can preferably be from 5% to 30%, and more preferably from 10% to 20%. Under high power conditions, the total WAR can preferably be from 20% to 45%, and more preferably from 30% to 40%.

[0063] Introducing the amount of steam discussed above such that all of the steam 128 flows through the primary combustion zone 135 can cause problems with flame stability and flame dynamics in the combustor 130. Preferably, the WAR of the primary air 152 flowing into the primary combustion zone 135 (primary air WAR) can be from 3% to 15%, and more preferably from 5% to 10%. Keeping the primary air WAR less than 15%, such as less than 10%, helps to maintain proper flame stability and dynamics, avoiding, for example, flameout in cases where a high total WAR is required. A primary air WAR of 3% or higher, such as 5% or higher, is preferably for maintaining flame stability and preventing hot spots from occurring within the burner, especially for highly reactive fuels such as hydrogen. Additionally, a primary air WAR value below 3% may not provide any benefits to the system, such as improved fuel combustion. Since the flow rate of the primary steam 232 injected at the primary steam injection location 222 is limited to achieve the primary air WAR discussed above, the remainder of the steam 128 is injected into the core air flow path 33 at one or more locations downstream of the primary combustion zone 135, and these locations are referred to herein as downstream steam injection locations.

[0064] In the case where steam 128 is injected into the mixing chamber 146, due to the natural distribution of the compressor discharge pressure air 150 among multiple flow paths of the compressor discharge pressure air 150 downstream of the HPC 24, some of the primary steam 232 will combine with the dilution air 154 and the HPT cooling air 158 and be injected into the combustor 26 and the HPT 28 respectively. Thus, the steam 128 is introduced into the core air flow path 33 at a location downstream of the primary combustion zone 135, where the dilution air 154 and the HPT cooling air 158 flow into the hot gas path 78. However, under certain operating conditions, such as high power conditions with relatively high steam demand, this natural flow distribution may not be sufficient to maintain the primary air WAR at the level discussed above. Therefore, the steam delivery assembly 212 is fluidly connected to the core air flow path 33 to inject the steam 128 at other downstream locations, independent of the steam 128 injected into the primary air 152. In Figure 3A the solid arrows are used to illustrate the flow path of the steam 128, the long dashed lines are used to illustrate the flow of the mixture of the compressed air 65 and the steam 128, and the long dashed double-dotted lines are used to illustrate the flow of the compressor bleed air 159.

[0065] The steam delivery assembly 212 can be fluidly connected to the HPT 28 to directly inject a portion of the steam 128 into the HPT 28. For example, the steam delivery assembly 212 can be fluidly connected to an outlet formed in the HPT stator vanes 68 of the HPT 28, such as an orifice, to selectively inject the HP turbine nozzle steam 234 into the core air flow path 33. This steam injection location is referred to herein as the HP turbine nozzle steam injection location 224. The first steam injection system 200 includes one or more steam flow control valves for selectively directing the steam 128 into the core air flow path 33 and controlling the distribution of the steam 128 among different injection locations. Each steam flow control valve discussed herein is a flow control valve that controls the flow rate of the steam 128 passing through the flow control valve. The steam control valve can be a proportional control valve that can be positioned to proportionally direct the steam 128 to multiple different locations, such as a three-way valve that can be positioned to proportionally direct the steam flowing through the steam flow control valve to one of two outlets. Additionally, two or more flow control valves can be configured to produce a similar control, and such flow control valves can have a closed position and multiple open positions, including a fully open position. The flow control valve can be an electrically operated valve, a hydraulically operated valve, or a pneumatically operated valve. When the flow control valve is hydraulically operated, the hydraulic fluid can be a suitable fluid of the turbine engine 10, such as including the fuel 67, lubricating oil, etc. As will be discussed in more detail below, these steam flow control valves are located in the steam delivery assembly 212 to direct a portion of the steam 128 to one or more steam injection locations 220 in the core air flow path 33.

[0066] As Figure 3A shown, the first steam injection system 200 includes an HP turbine nozzle steam flow control valve 242 that is operable to control the flow of HP turbine nozzle steam 234 into the HPT stator vanes 68. Although the HP turbine nozzle steam 234 may be injected as pure steam (without being mixed with additional air), the HP turbine nozzle steam 234 may also be mixed with air, such as a portion of the dilution air 154, for example, using one or more steam injector nozzles with an integrated venturi tube.

[0067] The steam delivery assembly 212 may also be directly fluidly connected to a cooling passage formed in the HPT rotor blades 70, bypassing the mixing chamber 146, to inject a portion of the steam 128 (referred to herein as HP turbine blade steam 236) into the HPT 28 via the HPT rotor blades 70. The HP turbine blade steam 236 may be injected through an opening (e.g., an orifice) formed in the HPT rotor blades 70. As Figure 3A shown, the first steam injection system 200 includes an HP turbine blade steam flow control valve 244 that is operable to control the flow of HP turbine blade steam 236 into the HPT rotor blades 70. Similar to the HP turbine nozzle steam 234, the HP turbine blade steam 236 may be injected as pure steam into the HPT 28, but the HP turbine blade steam 236 may also be mixed with air, such as the HPT cooling air 158. This steam injection location is referred to herein as the HP turbine blade steam injection location 226.

[0068] As described above, Figure 3A the HPT 28 shown in [reference] has one stage. If the HPT 28 has more than one stage, the HP turbine nozzle steam 234 and the HP turbine blade steam 236 may be directed through openings in any stage or all stages.

[0069] Although it is preferred to have the total WAR of the steam flowing through the HPT 28, a portion of the steam 128 (referred to herein as LP turbine steam 238) may be directed into the LPT 30 through an opening formed in one or more LPT rotor blades 74 (such as the first stage LPT rotor). More specifically, the LPT rotor blades 74 may include a cooling passage formed in the LPT rotor blades 74 through which cooling air (such as compressor bleed air 159 withdrawn from a stage of the HPC 24) flows. The compressor bleed air 159 may then be discharged from the cooling air passage through a plurality of openings (e.g., orifices) formed in the LPT rotor blades 74. Figure 3ATwo different airflows of compressor bleed air 159 are depicted, specifically, high-pressure compressor bleed air 159a and low-pressure compressor bleed air 159b. The high-pressure compressor bleed air 159a is withdrawn from a later stage (e.g., the sixth, seventh, or eighth stage) of the HPC 24, while the low-pressure compressor bleed air 159b is withdrawn from an earlier stage (e.g., the third or fourth stage) of the HPC 24. Accordingly, the pressure of the high-pressure compressor bleed air 159a is higher than that of the low-pressure compressor bleed air 159b. The high-pressure compressor bleed air 159a can be used to cool the first stage of the LPT 30, while the low-pressure compressor bleed air 159b can be used to cool the later stages of the LPT 30 and for other cooling purposes, such as the after-tank 37. As Figure 3A shown, the LP turbine steam 238 can be mixed with the compressor bleed air 159 to be discharged through the openings in the LPT rotor blades 74, and more specifically, with the high-pressure compressor bleed air 159a. Alternatively, the LP turbine steam 238 can be injected as pure steam. Although described as being injected through the LPT rotor blades 74, the LP turbine steam 238 or a portion thereof can additionally or alternatively be injected into the LPT 30 through the LPT stator vanes 72. This steam injection location is referred to herein as the LP turbine steam injection location 228. As Figure 3A shown, the first steam injection system 200 includes an LP turbine steam flow control valve 246 that is operable to control the flow of the LP turbine steam 238 into the LPT 30, and more specifically into the LPT rotor blades 74, and additionally or alternatively into the LPT stator vanes 72.

[0070] As Figure 3A shown, the steam 128 flows into the steam delivery assembly 212 through the steam inlet 214 and then sequentially through the LP turbine steam flow control valve 246, the HP turbine nozzle steam flow control valve 242, and the HP turbine blade steam flow control valve 244, each of which is located in the steam delivery assembly 212. As discussed above, these steam flow control valves can be proportional control valves. The steam 128 flowing into the steam inlet 214 reaches the first steam flow control valve, as Figure 3A shown, which is the LP turbine steam flow control valve 246, and a portion of the steam 128 can be directed as the LP turbine steam 238 by the LP turbine steam flow control valve 246, and the remaining steam flows to the second steam flow control valve. As Figure 3AAs shown, the second steam flow control valve is the HP turbine nozzle steam flow control valve 242, and a portion of the steam can be directed as HP turbine nozzle steam 234 by the HP turbine nozzle steam flow control valve 242, with the remaining steam flowing to the third steam flow control valve. The third steam flow control valve is the HP turbine blade steam flow control valve 244, and a portion of the steam can be directed as HP turbine blade steam 236 by the HP turbine blade steam flow control valve 244, with the remaining steam being the main steam 232. Thus, each steam flow control valve can be selectively operable to inject steam 128 at a desired flow rate, a desired total WAR, or both, while maintaining the main air WAR below a threshold.

[0071] The first steam injection system 200 further includes a controller 250. The controller 250 can be a separate, stand-alone controller operable as described herein, or can be another controller of the turbine engine 10, such as an engine controller. The engine controller can be a full authority digital engine control (FADEC). The controller 250 is configured to operate various aspects of the first steam injection system 200, including (in this embodiment) the HP turbine nozzle steam flow control valve 242, the HP turbine blade steam flow control valve 244, and the LP turbine steam flow control valve 246. In this embodiment, the controller 250 is a computing device having one or more processors 252 and one or more memories 254. The processor 252 can be any suitable processing device, including but not limited to a microprocessor, a microcontroller, an integrated circuit, a logic device, a programmable logic controller (PLC), an application specific integrated circuit (ASIC), and / or a field programmable gate array (FPGA). The memory 254 can include one or more computer-readable media, including but not limited to non-transitory computer-readable media, computer-readable non-volatile media (e.g., flash memory), RAM, ROM, a hard disk drive, a flash drive, and / or other memory devices.

[0072] The memory 254 can store information accessible by the processor 252, including computer-readable instructions executable by the processor 252. The instructions can be any set of instructions or sequence of instructions that, when executed by the processor 252, cause the processor 252 and the controller 250 to perform operations. In some embodiments, the instructions can be executed by the processor 252 to cause the processor 252 to complete any operations and functions for which the controller 250 is configured, as will be further described below. The instructions can be software written in any suitable programming language and can also be implemented in hardware. Additionally, and / or alternatively, the instructions can be executed in logically and / or virtually independent threads on the processor 252. The memory 254 can also store data accessible by the processor 252.

[0073] The technology discussed in this document relates to computer-based systems and the actions taken by and the information sent to and from computer-based systems. Those of ordinary skill in the art will recognize that the inherent flexibility of computer-based systems allows for a variety of possible configurations, combinations, and divisions of tasks and functions among and within components. For example, the processes discussed herein can be implemented using a single computing device or multiple computing devices working in combination. Databases, memories, instructions, and applications can be implemented on a single system or distributed across multiple systems. Distributed components can operate sequentially or in parallel.

[0074] Figure 3B is similar to Figure 3A a detailed view showing a portion of a turbocharged engine 16 and a second steam injection system 201 according to another preferred embodiment. In Figure 3B the second steam injection system 201 shown in Figure 3A the main steam 232 is injected at an alternative main steam injection location 222a. More specifically, the main steam 232 is injected into the mixer assembly 140. In this way, the main steam 232 can be directly injected into the main combustion region 135. This configuration can be used as Figure 3A an alternative to the configuration shown in Figure 3B or as a supplement to the configuration shown in Figure 3A such that a portion of the main steam 232 is injected into the mixing chamber 146 while another portion is injected into the mixer assembly 140.

[0075] Figures 4 to 6 shows an additional embodiment of a steam injection system that can be used in the turbine engine 10 discussed herein. In the following discussion, the same reference numerals will be used to refer to the same or similar components in the steam injection systems discussed herein, including the first steam injection system 200 discussed above. The discussion of these components in one embodiment applies to other embodiments, and the detailed description of these components and features is omitted in the following discussion. Additionally, Figures 4 to 6 shows the main steam 232 being injected into the mixing chamber 146, but Figure 3B the configuration shown in

[0076] Figure 4 is similar to Figure 3AA detailed view showing a portion of a turbocharged engine 16 and a third steam injection system 202 according to another preferred embodiment. In the first steam injection system 200, a plurality of steam flow control valves are used to direct the steam 128 flow from the steam inlet 214 to each of the plurality of steam injection locations 220, but other arrangements of steam flow control valves other than those shown in Figure 3A may be used. In the third steam injection system 202 shown in Figure 4 , for example, one steam flow control valve, referred to herein as a proportional steam flow control valve 260, may be used. The proportional steam flow control valve 260 includes a steam inlet 214 for allowing the steam 128 to flow into the proportional steam flow control valve 260. The proportional steam flow control valve 260 includes a plurality of outlets, each outlet corresponding to one of the plurality of steam injection locations 220 discussed above. The controller 250 may be operatively coupled to the proportional steam flow control valve 260 to position the valve and regulate the portion of the steam 128 flowing to each of the plurality of steam injection locations 220 (e.g., regulate the amount or flow rate of the main steam 232, HP turbine nozzle steam 234, HP turbine blade steam 236, and LP turbine steam 238).

[0077] Figure 5 is a detailed view similar to Figure 3A showing a portion of a turbocharged engine 16 and a fourth steam injection system 203 according to another preferred embodiment. As discussed above, a portion of the steam 128 may be injected into the combustion chamber 130 at a location downstream of the main combustion zone 135. In the first steam injection system 200, this steam is mixed with the dilution air 154, however, in this embodiment, a portion of the steam 128 flows as burner liner steam 270 into a burner liner channel 272 surrounding the burner liner, such as the outer liner 134 shown in Figure 5 , and then enters the combustion chamber 130 through steam holes 274 in the outer liner 134 located downstream of the main combustion zone 135. In addition to adding mass flow to the combustion gases 66, the burner liner steam 270 may also be used to help cool the burner liner, such as the outer liner 134. The steam holes 274 are another one of the plurality of steam injection locations 220, and the fifth steam injection system 204 includes a burner liner steam flow control valve 276 that operates in a manner similar to the HP turbine nozzle steam flow control valve 242, HP turbine blade steam flow control valve 244, or LP turbine steam flow control valve 246 discussed above.

[0078] In this embodiment, the burner liner passage 272 can also be a flow passage for dilution air 154. The blocking door 278 can be positioned at the upstream end of the burner liner passage 272. The blocking door 278 is selectively operable to regulate the flow rate of dilution air 154 entering the burner liner passage 272. The blocking door 278 can be moved between a fully closed position and a fully open position by a suitable moving mechanism. The fully closed position blocks the flow of dilution air 154 into the burner liner passage 272, and the fully open position allows dilution air 154 to flow into the burner liner passage 272. In some embodiments, the blocking door 278 can include a plurality of intermediate positions for regulating the flow rate of dilution air 154 flowing into the burner liner passage 272. Closing the blocking door 278 can reduce the flow rate of dilution air 154 flowing into the burner liner passage 272, increase the amount of air flowing as primary air 154, and reduce the primary WAR. Therefore, the operation of the blocking door 27 (either in combination with or separately from the burner liner steam flow control valve 276) can control the primary WAR. The blocking door 278 can be operated by a suitable moving mechanism, such as an actuator (e.g., a hydraulic actuator or an electric actuator) or a motor.

[0079] Figure 6 is similar to Figure 3A a detailed view showing a portion of the turbocharged engine 16 and the fifth steam injection system 204 according to another preferred embodiment. Under some conditions, in addition to (or instead of) steam 128, liquid water (e.g., water 124( Figure 2 )) can be injected into the core air flow path 33. Figure 6 The steam delivery assembly 212 of the fifth steam injection system 204 shown in Figure 2 is fluidly connected to a water source, such as the water tank 112 of the steam system 100, as

[0080] The steam delivery assembly 212 includes a water inlet 216 and an inlet flow control valve 218 fluidly connected to the steam inlet 214 and the water inlet 216. The inlet flow control valve 218 can be a proportional flow control valve that controls the amounts of steam 128 and water 124 flowing into the steam delivery assembly 212 from the steam inlet 214 and the water inlet 216, respectively. The inlet flow control valve 218 can operate in a manner similar to the steam flow control valve discussed above. When receiving water 124, the steam delivery assembly 212 is fluidly coupled to a plurality of steam injection locations and distributes the water 124 to the plurality of steam injection locations for injecting the water 124 at the plurality of steam injection locations. The inlet flow control valve 218 can be used to control the relative amounts of water 124 and steam 128 distributed by the steam delivery assembly 212 and subsequently injected into the core air flow path 33. The inlet flow control valve 218 can be positioned (i.e., operated) to provide pure steam 128, water 124, or a mixture of both.

[0081] Figure 7 is similar to Figure 3A is a detailed view showing a portion of the turbocharged engine 16 and the sixth steam injection system 205 according to another preferred embodiment. Instead of injecting all of the steam 128 into the core air flow path 33, some of the steam 128 can be diverted from the core air flow path 33, thereby reducing the total amount of steam 128 injected into the core air flow path 33. Accordingly, each of the HP turbine nozzle steam flow control valve 242, the HP turbine blade steam flow control valve 244, and the LP turbine steam flow control valve 246 is fluidly connected to a vent 280 to discharge or bypass the core air flow path 33, and each of these steam flow control valves is operable to direct at least a portion of the steam 128 to the vent 280. The vent 280 can discharge the unwanted steam 128 overboard or back into the steam system 100, such as into the condenser 104, for recovery by the steam system 100.

[0082] By injecting steam 128 at a plurality of steam injection locations 220 using any of the steam injection systems discussed above into the core air flow path 33, the WAR can be selectively controlled along the core air flow path 33. The core air can have a lower WAR in the downstream section of the core air flow path 33, and more specifically, in the hot gas path 78, where additional steam 128 can be added to increase the WAR when the combustion gas 66 flows into the turbine section 27. More specifically, the primary air WAR can be maintained below a threshold to maintain the stability and dynamics of the flame in the primary combustion zone 135 of the combustor 130, and the primary air WAR threshold can be, for example, the upper limit of the range discussed above. More preferably, the primary air WAR can be maintained within the range discussed above. In the case where the primary air WAR is maintained within the desired range, additional steam 128 can be added downstream to achieve a desired total WAR that is higher than the primary air WAR, thus providing for efficient operation of the turbine engine 10.

[0083] The steam injection systems and turbine engine 10 discussed herein can be controlled using the following methods. The following discussion will generally refer to Figure 3A the first steam injection system 200 shown in, but is applicable to the other steam injection systems discussed herein. These methods can be implemented by a controller 250, and the controller 250 can be configured to perform the steps of the methods discussed below. More details of the method are described above with respect to the operation and description of the above components.

[0084] A method of operating the turbine engine 10 can include controlling the amount of steam injected at an upstream steam injection location (i.e., the primary steam injection location 222 or an alternative primary steam injection location 222a ( Figure 3B )) to maintain the WAR of the primary air 152 below a primary air water - air ratio threshold. The method can also include controlling the amount of steam injected at one or more of the downstream steam injection locations in the downstream steam injection locations, such as those discussed above, to achieve a total water - air ratio in the core air flow path at a location downstream of the burner. The method can include selectively controlling any of the steam flow control valves discussed above to selectively provide steam 128 at a desired WAR.

[0085] A method of operating a turbine engine 10 may further include determining a desired total WAR of core air 64 flowing through a core air flow path 33. The determination may be based on a desired throttle position or other indication of a desired power level of the turbine engine 10. When the method is executed by a controller 250, the controller 250 may be configured to receive an input (such as an input indicative of a power level) and determine the desired total WAR based on the received input. The input may be, for example, a throttle input. Additionally or alternatively, the controller 250 may be coupled to one or more sensors 256, such as a plurality of sensors. Such sensors 256 may be, for example, temperature sensors, pressure sensors, or flow sensors. The sensors 256 may be positioned at various suitable locations within the turbine engine 10, including within the core air flow path 33. For example, one of the plurality of sensors 256 may be positioned upstream of the combustor 26, such as at the compressor discharge outlet 144, within the mixing chamber 146, or as part of the mixer assembly 140. Another of the plurality of sensors 256 may be positioned within the hot gas path 78 downstream of the combustor 26 (i.e., the flow path of the combustion gases 66), such as at the nozzle (inlet) or outlet of the HPT 28 or LPT 30. The controller 250 may receive inputs from the one or more sensors 256 and determine the power level of the turbine engine 10 or the flow rate of the core air 64 based on the inputs received from the sensors 256.

[0086] When the steam injection system includes a vent 280, such as Figure 7 the sixth steam injection system 205 shown in, the method may further include, when the total steam provided is greater than the desired total WAR, or the method may include operating one or more steam control valves to divert at least a portion of the steam 128 to the vent 280. The vent 280 may be particularly useful during transient conditions or fault conditions (such as flameout or in-flight engine restart). Injecting steam into the core air flow path 33 or at least the combustor 26 may cause difficulties in re-ignition, and thus, the method may include operating one or more steam control valves to divert the steam 128 to the vent 280 when a fault condition has occurred. The vent 280 may be fluidly coupled to an opening to discharge the steam 128 overboard, such as through one of the exhaust nozzles (e.g., the core exhaust nozzle 32( Figure 1 )) or the fan bypass nozzle 76( Figure 1 )) or alternatively, discharging the steam 128 back to the steam system 100( Figure 2 ), such as back to the condenser 104( Figure 2 ).

[0087] A further aspect of the present disclosure is provided by the subject matter of the following clauses.

[0088] A turbomachine for an aircraft, the turbomachine comprising: a turbocharged engine, a fan having a fan shaft coupled to the turbocharged engine, and a steam system. The turbocharged engine includes a core air flow path for allowing core air to flow therethrough, a combustor, an engine shaft, and a turbine. The combustor is positioned in the core air flow path to receive compressed air and is fluidly coupled to a fuel source to receive fuel. The fuel is injected into the combustor to mix with the compressed air to produce a fuel and air mixture. The fuel and air mixture burns in a main combustion zone of the combustor to produce combustion gases. The turbine is located downstream of the combustor to receive the combustion gases and rotate the turbine. The turbine is coupled to the engine shaft. The steam system extracts water from the combustion gases and vaporizes the water to produce steam. The steam system is fluidly coupled to the core air flow path at a plurality of steam injection locations to selectively inject the steam into the core air flow path at each of the plurality of steam injection locations to add mass flow to the core air. The plurality of steam injection locations include (i) an upstream steam injection location positioned to inject steam into the core air flow path at or upstream of the main combustion zone of the combustor, and (ii) a downstream steam injection location positioned to inject steam into the core air flow path downstream of the main combustion zone. The steam system includes a steam flow control valve operable to vary the distribution of the steam injected into the core air flow path at the plurality of steam injection locations.

[0089] The turbomachine according to the preceding clause, wherein the downstream steam injection location is one of a plurality of downstream steam injection locations.

[0090] The turbomachine according to any one of the preceding clauses, wherein the steam flow control valve is a proportional steam flow control valve fluidly connected to each of the plurality of downstream steam injection locations, the proportional steam flow control valve being operable to control the distribution of the steam to each of the plurality of downstream steam injection locations.

[0091] The turbomachine according to any one of the preceding clauses, wherein the steam flow control valve is fluidly connected to the upstream steam injection location to control the distribution of the steam to the upstream steam injection location.

[0092] A turbine engine according to any one of the preceding clauses, wherein the steam flow control valve is one of a plurality of said steam flow control valves, and the steam flow control valve is operable to vary the distribution of the steam injected into the core air flow path by the plurality of steam injection locations.

[0093] A turbine engine according to any one of the preceding clauses, wherein the turbine is a high-pressure turbine and the downstream steam injection location is in the high-pressure turbine.

[0094] A turbine engine according to any one of the preceding clauses, wherein the steam system includes a high-pressure turbine steam flow control valve to control the steam flow to the high-pressure turbine.

[0095] A turbine engine according to any one of the preceding clauses, wherein the high-pressure turbine includes a turbine rotor having a plurality of rotor blades, and the downstream steam injection location is the plurality of rotor blades.

[0096] A turbine engine according to the preceding clause, wherein cooling air is provided to the plurality of rotor blades and the steam is mixed with the cooling air.

[0097] A turbine engine according to any one of the preceding clauses, wherein the high-pressure turbine includes a plurality of stator vanes, and the downstream steam injection location is the plurality of stator vanes.

[0098] A turbine engine according to any one of the preceding clauses, wherein the high-pressure turbine includes a turbine rotor having a plurality of rotor blades, and the plurality of rotor blades are downstream of the plurality of stator vanes.

[0099] A turbine engine according to the preceding clause, wherein cooling air is provided to the plurality of stator vanes and the steam is mixed with the cooling air.

[0100] A turbine engine according to any one of the preceding clauses, wherein the turbocharged engine includes a high-pressure compressor positioned in the core air flow path upstream of the combustor to produce the compressed air.

[0101] A turbine engine according to any one of the preceding clauses, wherein the engine shaft is a high-pressure shaft.

[0102] A turbine engine according to any one of the preceding clauses, wherein the high-pressure compressor is driven by the high-pressure shaft to compress the core air flowing through the core air flow path and produce the compressed air.

[0103] A turbine engine according to any one of the preceding clauses, wherein the turbocharged engine includes a low-pressure compressor positioned upstream of the high-pressure compressor in the core air flow path to produce the compressed air.

[0104] A turbine engine according to any one of the preceding clauses, wherein the turbocharged engine includes a low-pressure turbine positioned downstream of the high-pressure turbine in the core air flow path to receive the combustion gases and rotate the turbine.

[0105] A turbine engine according to any one of the preceding clauses, wherein the turbocharged engine includes a low-pressure shaft, and the low-pressure turbine is coupled to the low-pressure shaft.

[0106] A turbine engine according to any one of the preceding clauses, wherein the downstream steam injection position in the high-pressure turbine is one of a plurality of downstream steam injection positions.

[0107] A turbine engine according to the preceding clause, wherein another downstream steam injection position of the plurality of downstream steam injection positions is located in the low-pressure turbine.

[0108] A turbine engine according to the preceding clause, wherein the low-pressure turbine includes a turbine rotor including a plurality of rotor blades, and the downstream steam injection position is the plurality of rotor blades.

[0109] A turbine engine according to any one of the preceding clauses, wherein another downstream steam injection position of the plurality of downstream steam injection positions is a part of the burner located downstream of the main combustion region.

[0110] A turbine engine according to the preceding clause, wherein the burner includes a burner liner, and the downstream steam injection position is a hole formed in the burner liner.

[0111] A turbine engine according to any one of the preceding clauses, wherein the turbocharged engine includes a compressor positioned upstream of the burner in the core air flow path to compress the core air and thereby produce the compressed air.

[0112] A turbine engine according to the preceding clause, wherein the compressor is driven by the high-pressure shaft to compress the core air flowing through the core air flow path and produce the compressed air.

[0113] A turbine engine according to any one of the preceding clauses, wherein the turbocharged engine includes a mixing chamber positioned upstream of the burner and downstream of the compressor to receive the compressed air, and the upstream steam injection location is the mixing chamber.

[0114] A turbine engine according to the preceding clause, wherein the steam and air are mixed in the mixing chamber to produce a steam-air mixture.

[0115] A turbine engine according to the preceding clause, wherein a portion of the steam-air mixture is provided as primary air to the burner.

[0116] A turbine engine according to any one of the preceding clauses, wherein a portion of the steam-air mixture is injected into the combustion gases downstream of the primary combustion zone.

[0117] A turbine engine according to any one of the preceding clauses, wherein the turbine is a high-pressure turbine, and the portion of the steam-air mixture injected into the combustion gases is injected into the high-pressure turbine.

[0118] A turbine engine according to the preceding clause, wherein the high-pressure turbine includes a turbine rotor including a plurality of rotor blades, and the portion of the steam-air mixture injected into the combustion gases is injected through the plurality of rotor blades.

[0119] A turbine engine according to any one of the preceding clauses, wherein the high-pressure turbine includes a plurality of stator vanes, and the portion of the steam-air mixture injected into the combustion gases is injected through the plurality of stator vanes.

[0120] A turbine engine according to any one of the preceding clauses, wherein a portion of the steam-air mixture is injected into the combustion chamber downstream of the primary combustion zone.

[0121] A turbine engine according to the preceding clause, wherein the burner includes a burner liner, and the portion of the steam-air mixture injected into the combustion chamber downstream of the primary combustion zone is injected through formed holes in the burner liner.

[0122] A turbine engine according to any one of the preceding clauses, wherein the downstream steam injection location is a portion of the burner downstream of the primary combustion zone.

[0123] A turbine engine according to the preceding clause, wherein the burner includes a burner liner, and the downstream steam injection location is a hole formed in the burner liner.

[0124] A turbine engine according to any one of the preceding clauses, wherein the turbine is a low-pressure turbine and the downstream steam injection location is in the low-pressure turbine.

[0125] A turbine engine according to the preceding clause, wherein the low-pressure turbine includes a turbine rotor, the turbine rotor includes a plurality of rotor blades, and the downstream steam injection location is the plurality of rotor blades.

[0126] A turbine engine according to any one of the preceding clauses, wherein the steam system includes a steam delivery assembly, the steam delivery assembly includes a steam inlet for receiving the steam generated by the steam system; and a water inlet fluidly connected to a water source to receive water from the water source.

[0127] A turbine engine according to the preceding clause, wherein the steam delivery assembly is fluidly connected to the plurality of steam injection locations to inject the steam and the water into the core air flow path at the plurality of steam injection locations.

[0128] A turbine engine according to any one of the preceding clauses, wherein the steam flow control valve is located in the steam delivery assembly and is operable to change the distribution of the steam, the water, or both injected into the core air flow path.

[0129] A turbine engine according to any one of the preceding clauses, wherein the steam delivery assembly further includes an inlet flow control valve, the inlet flow control valve is fluidly connected to the steam inlet and the water inlet, and is operable to control the relative amounts of the water and the steam distributed by the steam delivery assembly.

[0130] A turbine engine according to the preceding clause, wherein the water source is a water tank.

[0131] A turbine engine according to the preceding clause, wherein the steam system includes a water tank.

[0132] A turbine engine according to the preceding clause, wherein the water tank is an accumulator positioned downstream of the water separator to collect and store water.

[0133] A turbine engine according to any one of the preceding clauses, wherein the steam system includes a vent, and the steam flow control valve is fluidly connected to the vent and is operable to direct at least a portion of the steam to the vent, thereby bypassing the core air flow path.

[0134] The turbine engine according to any one of the preceding clauses further includes a controller operably coupled to the steam flow control valve to adjust the position of the steam flow control valve.

[0135] The turbine engine according to the preceding clause, wherein the controller is configured to position the steam flow control valve to distribute the steam to the plurality of steam injection locations to provide a desired total water-air ratio for the core air flowing through the core air flow path.

[0136] The turbine engine according to any one of the preceding clauses, wherein the controller is configured to maintain the water-air ratio of the primary air flowing into the primary combustion zone below a primary air water-air ratio threshold.

[0137] The turbine engine according to the preceding clause, wherein the primary air water-air ratio threshold is from 3% to 15%.

[0138] The turbine engine according to any one of the preceding clauses, wherein the primary air water-air ratio threshold is from 5% to 10%.

[0139] The turbine engine according to any one of the preceding clauses further includes a sensor located in the core air flow path and coupled to the controller in parallel, the controller being configured to receive an input from the sensor and adjust the position of the steam flow control valve based on the input received from the sensor.

[0140] The turbine engine according to any one of the preceding clauses further includes a plurality of sensors located in the core air flow path and coupled to the controller in parallel, the controller being configured to receive an input from each of the plurality of sensors and adjust the position of the steam flow control valve based on the input received from the plurality of sensors.

[0141] The turbine engine according to the preceding clause, wherein one of the plurality of sensors is positioned upstream of the burner.

[0142] The turbine engine according to the preceding clause, wherein one of the plurality of sensors is positioned upstream of the burner and downstream of the compressor.

[0143] The turbine engine according to any one of the preceding clauses, wherein one of the plurality of sensors is positioned in the flow path of the combustion gas, downstream of the burner.

[0144] A turbine engine according to any one of the preceding clauses, wherein one of the plurality of sensors is positioned in the flow path of the combustion gases, downstream of the burner and upstream of the turbine.

[0145] A turbine engine according to any one of the preceding clauses, wherein the engine shaft is a low-pressure shaft and the turbine is a low-pressure turbine.

[0146] A turbine engine according to any one of the preceding clauses, wherein the fan shaft is coupled to the low-pressure shaft to be driven by the low-pressure shaft.

[0147] A turbine engine according to any one of the preceding clauses, further comprising a nacelle circumferentially surrounding the fan.

[0148] A turbine engine according to any one of the preceding clauses, wherein the fan comprises a plurality of fan blades that rotate to generate a volume of air.

[0149] A turbine engine according to the preceding clause, wherein the nacelle defines a bypass air flow passage between the nacelle and the turbocharged engine. The volume of air from the fan is diverted and flows as bypass air into the bypass air flow passage and as core air into the core air flow path.

[0150] A turbine engine according to any one of the preceding clauses, wherein the steam system comprises a boiler located downstream of the burner, the boiler receiving the extracted water and being fluidly connected to the burner to receive the combustion gases and boil the water to produce the steam.

[0151] A turbine engine according to the preceding clause, wherein the steam system comprises a steam turbine. The steam turbine is fluidly connected to the boiler to receive the steam from the boiler and rotate the steam turbine.

[0152] A turbine engine according to the preceding clause, wherein the steam turbine is coupled to the engine shaft.

[0153] A turbine engine according to any one of the preceding clauses, wherein the steam system comprises a steam delivery assembly that is fluidly connected to the plurality of steam injection locations to inject the steam and the water into the core air flow path at the plurality of steam injection locations.

[0154] A turbine engine according to any one of the preceding clauses, wherein the steam delivery assembly comprises a steam inlet for receiving the steam generated by the steam system.

[0155] A turbine engine according to any one of the preceding clauses, wherein the steam flow control valve is located in the steam delivery assembly and is operable to vary the distribution of the steam injected into the core air flow path.

[0156] A turbine engine according to any one of the preceding clauses, wherein the steam delivery assembly is fluidly coupled to the steam system downstream of the steam turbine to receive the steam from the steam turbine.

[0157] A turbine engine according to any one of the preceding clauses, wherein the steam system includes a condenser located downstream of the turbine for receiving the combustion gases and condensing the water from the combustion gases.

[0158] A turbine engine according to the preceding clause, wherein the condenser is located downstream of the boiler.

[0159] A turbine engine according to any one of the preceding clauses, wherein the condenser is located in the bypass air flow passage for cooling the bypass air to the combustion gases and condensing the water from the combustion gases.

[0160] A turbine engine according to any one of the preceding clauses, wherein the steam system includes a water separator located downstream of the condenser, the water separator separating the water from the exhaust-water mixture.

[0161] A turbine engine according to any one of the preceding clauses, wherein the water separator is fluidly connected to the boiler to supply the water to the boiler.

[0162] A turbine engine according to the preceding clause, wherein the water separator is a cyclone separator.

[0163] A turbine engine according to the preceding clause, further comprising a water pump fluidly communicating with the water separator and the boiler to direct the water flow from the water separator into the boiler.

[0164] A method of operating a turbine engine of an aircraft having a steam system. The method includes injecting steam into a core air flow path at a plurality of steam injection locations. The plurality of steam injection locations include (i) an upstream steam injection location positioned to inject steam into the core air flow path at or upstream of a primary combustion zone of a combustor; and (ii) a downstream steam injection location positioned to inject steam into the core air flow path downstream of the primary combustion zone. The method further includes controlling the amount of steam injected at the upstream steam injection location to maintain the water-air ratio of the primary air flowing into the primary combustion zone below a primary air water-air ratio threshold, and controlling the amount of steam injected at the downstream steam injection location to achieve a desired total water-air ratio in the core air flow path at a location downstream of the combustor.

[0165] The method according to the preceding item, wherein the primary air water-air ratio threshold is from 3% to 15%.

[0166] The method according to any one of the preceding items, wherein the primary air water-air ratio threshold is from 5% to 10%.

[0167] The method according to any one of the preceding items, further comprising determining the desired total water-air ratio of the core air flowing through the core air flow path of the turbine engine.

[0168] The method according to any one of the preceding items, operating the turbine engine according to any one of the preceding items.

[0169] The method according to any one of the preceding items, further comprising a controller configured to perform the method according to any one of the preceding items.

[0170] Although the above description is directed to preferred embodiments, other variations and modifications will be apparent to those skilled in the art and may be made without departing from the spirit or scope of the disclosure. Additionally, features described in connection with one embodiment may be used in combination with other embodiments even if not explicitly stated above.

Claims

1. A turbine engine for an aircraft, characterized in that: The turbine engine comprises: A turbocharged engine, the turbocharged engine comprising: a core air flow path for flowing core air therethrough; a combustor positioned in the core air flow path to receive compressed air and fluidly coupled to a fuel source to receive fuel, the fuel being injected into the combustor to mix with the compressed air to produce a fuel and air mixture that is combusted in a primary combustion zone of the combustor to produce combustion gases; engine shaft; and a turbine located downstream of the combustor to receive the combustion gases and rotate the turbine, the turbine being coupled to the engine shaft; a fan having a fan shaft coupled to the turbocharged engine; and A steam system that extracts water from the combustion gases and vaporizes the water to produce steam, the steam system being fluidly coupled to the core air flow path at a plurality of steam injection locations to selectively inject the steam into the core air flow path at each of the plurality of steam injection locations to add mass flow to the core air, the plurality of steam injection locations comprising (i) an upstream steam injection location positioned to inject steam into the core air flow path at or upstream of the primary combustion zone of the burner, and (ii) a downstream steam injection location positioned to inject steam into the core air flow path downstream of the primary combustion zone, the steam system comprising a steam flow control valve operable to vary the distribution of the steam injected into the core air flow path at the plurality of steam injection locations.

2. The turbine engine according to claim 1, characterized in that The turbocharged engine comprises: a compressor positioned in the core air flow path upstream of the combustor to compress core air to produce the compressed air; and A mixing chamber is positioned upstream of the combustor and downstream of the compressor to receive the compressed air, the upstream steam injection location being the mixing chamber.

3. The turbine engine according to claim 1, characterized in that: wherein the steam flow control valve is one of a plurality of the steam flow control valves operable to vary the distribution of the steam injected into the core air flow path by the plurality of steam injection locations.

4. The turbine engine according to claim 1, characterized in that: Wherein the steam system includes a vent, and the steam flow control valve is fluidly connected to the vent and is operable to direct at least a portion of the steam to the vent, bypassing the core air flow path.

5. The turbine engine according to claim 1, characterized in that The steam system comprises a steam delivery assembly, wherein the steam delivery assembly comprises: a steam inlet for receiving the steam generated by the steam system; and a water inlet fluidly coupled to a water source to receive water from the water source, wherein the steam delivery assembly is fluidly coupled to the plurality of steam injection locations to inject the steam and the water into the core air flow path at the plurality of steam injection locations, and Wherein, the steam flow control valve is located in the steam delivery assembly and is operable to vary the distribution of the steam, the water, or both injected into the core air flow path.

6. The turbine engine according to claim 5, characterized in that Wherein the steam delivery assembly further comprises an inlet flow control valve fluidly connected to the steam inlet and the water inlet and operable to control relative amounts of the water and the steam dispensed by the steam delivery assembly.

7. The turbine engine according to claim 1, characterized in that The downstream steam injection location is a portion of the combustor downstream of the primary combustion zone.

8. The turbine engine according to claim 7, characterized in that Wherein the combustor includes a combustor liner, the downstream steam injection location is a hole formed in the combustor liner.

9. The turbine engine according to claim 1, characterized in that Wherein the turbine is a low pressure turbine, the downstream steam injection location is located in the low pressure turbine.

10. The turbine engine according to claim 9, characterized in that Wherein the low-pressure turbine comprises a turbine rotor, the turbine rotor comprises a plurality of rotor blades, and the downstream steam injection location is the plurality of rotor blades.

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